Railway-traffic-controlling system.



A.V.T .DAY. RAILWAY TRAFFIC CONTROLLING SYSTEM.

APPLICATION FILED JUNE 15. I908.

1,144,465. Patented June 29, 1915.

nll- NORRIS FILTERS L'O.. PHOTO LIIHOY, WASHINGTON. D t

ALBERT V. T. DAY, OF NEW ROCHELLE, NEW YORK, ASSIGNOR, IBY MESNE ASSIGN-MENTS, T0 HALL SWITCH & SIGNAL COMPANY, OF NEW YORK, N. Y., A COR-PORATION OF MAINE.

RAILWAY-TRAFFIG-CONTROLLING SYSTEM.

Specification of Letters Patent.

Patented June 29, 1915.

Application filed June 15, 1908. Serial No. 438,593.

To all whom it may concern Be it known that I, ALBERT V. T. DAY, acitizen of the United States, residing at New Rochelle, in the county ofWestchesterand State of New York, have invented a certain new and usefulImprovement in Railway- Traftic-Controlling Systems, of which thefollowing is a specification, reference being had therein to theaccompanying drawings, forming part thereof.

My invention relates broadly to electric automatic railwaytraffic-controlling systems, and relates particularly to that class ofsuch systems known as block signal S375.

tems, wherein. the trafiic is controlled by the display of visualsignals.

The object of the invention is to produce a system of this characterwhich shall be simple and reliable, and which may, in its preferredembodiment, be applied to electric railroads employing direct oralternating traction currents, and without interference with the use ofthe track rails for the transmission of traction current, and withoutliability of the signals to be falsely actuated by traction current.

An important feature of my invention consists in the means of operatingthe signals on the normal danger plan.

Another important feature consists in the means of selectivelycontrolling the home and distant signals by a common line cir-' cuit.

These features and many others will appear more in detail in thefollowing description of that particular embodiment of my inventionwhich is illustrated in the accompanying drawing.

The drawing is a diagram showing a single track and three signalstations thereon, designated respecively as A, B and C.

The apparatus at the three stations illustrated are identical incharacter, andfor this reason similar reference numbers are used todesignate corresponding parts of the apparatus, but in thisspecification the reference letters A, B and C are added to thereference numbers, where necessary, to indicate at which station thepart referred to is located.

The track rails are designated by the reference character 1, and as thesystem is applicable to an electric railroad in which the track railsare used as a part of the tractioncurrent circuit, a third rail ortrolley wire 3 is illustrated, together with an alternating currentgenerator at which furnishes the traction current and has its respectiveterminals connected to the track rails and the third rail. However, thetraction current does not necessarily either contribute to, or interferewith, the operation of the signal. system in any manner.

The relays and other signal apparatus are actuated by alternatingcurrents or periodic currents of equivalent character, and thearrangement of the track circuits is similar to the arrangementdisclosed in the application of Clyde J. Coleman, filed July 12, 1907,Serial Number 383,366. The rails 1 are bonded continuously, so as toform uninterrupted conductors for the traction current, and at eachdivision between blocks is a heavy cross-bond 2. The signals 5 and 6 arecontrolled primarily by alternating currents produced in the rails bymeans of stepdown transformers 7, of which the second ary terminals areconnected to the two rails respectively. The transformers are suppliedwith current from transmission wires 8 and 9 fed by an alternatingcurrent generator 11, and the wires 8 and 9 furnish current for all thesignal-controlling apparatus.

The transformers '7 are connected with the rails at or near the middleof each block, and this arrangement results in the equal division of thecurrents from their secondary terminals. In the block A-B, for example,one-half of the alternating current passes from the transformer by onerail to crossbond 2 and thence back by the other rail to thetransformer; and the other half of the current passes by one rail tocross-bond 2 and back by the other rail. All the transformers 7 areconnected to the track rails so as to deliver currents of like polarityto the corresponding rails of their respective blocks at any giveninstant. The object of this mode of connecting the track supplytransformers is to prevent the current of the transformer of one blockfrom effectually energizing the track relays ,of the adjacent blocks;and the reasons why this mode of connection accomplishes this resultwill appear hereinafter.

The signal controlling relays are responsive to the currents in thetrack circuits through track coils 12 and 13. These coils are locatedclose to the rails at each end of each block and are energized byalternating currents induced in them by the alternating currents\fiowing, as 1 above described, through the rails and the cross-bonds.Although, in the drawing, these coils appear to occupy a substantialportion "of each block, it will be understood that they occupy, in fact,only a short length of'the track at each side of a c1ioss bond,.and thusif a train be in any part of a block it will act, until itzZLIIiVGS atthe end ,thereof, :to denergize the track coil at one or:bothiends ofthe block, =-since ,the car wheels and axles act as a cross-bond.anchsliunt the alternating current. away from the ends of-the; trackcircuit. where the track coils are located.

The .track coils .12 and 13 are ,connected withtrackrclays Hand 15,,which directly control the line circuits conneetingithc, signalstations, andthus control the line i relays which in turn control :thesignals. These track relays are .of the alternating-current type, in:which a field constantlyenergized by alternating current acts upon a.movable armature which is provided with a coiLand a contact finger.When .the armature coil is energized withan alternatingcurrent havingthe same frequency as current in the field and having a certain phaserelation thereto, thearmature is moved andheld in single-clearingposition, while the interruption oiiothe currentin thearmature permitsit to be retracted by gravity or -.a spring to open-circuit position.Areversalof phase of current in .the armature coil would also tend toretract .the armature from signalclearing position. .For brevityIshallhereina'fter designate thisgeneral form of. relay as. a polarized'alternating-current relay, or. a polarizedperiodic current relay. Thecombination .otsuch (polarized relays with. track circuits whicharelimited or demarcated'by cross-bonds of low impedance and controltherelays through inductive track coils, is unimportant .featureof myinvention. By employing such relays in the said combination byconnecting the .track supply transformers ofthe various bloclrsso that:they all deliver the same instantaneous polarity to the track rails,ILam. enabled to insure; against the false signal-clearing actuation ofarelay of one'bloc'k by current from an adjacent block, when:the relayshould not be. actuated to clearfits signal. For example, suppose .atrain to be located in the block A-B between its supply transformer 7and its advance traclccoil 12. Obviouslynow the relay 1 1 controlledbythe track coil 12 is required ,to remainlin position toholdits-signals 5 -and 6 at danger. But if the cross-bond2 has beenaccidentally broken, a currentwill'fiow fromtheitransformer 7 oftheblock BC rearward through the track railsand around the .track coil12 and through the avheels and axles of the train in rear of the coil 12Thus the coil 12 will be energized and W111 energize the armature of itspolarized I alter- "natingrelay I 1 -but the direction of flow of thiscurrent iromthe blodr- B-C around the track coil 12 will be just thereverse of "the direction ofnormal flow of current of the block ABaround the track coil 123, so that this'track coil, when energizedby'the block :B-:C, willrexcite the relay armature reversely so as tomove it into position to keep the signals 5 ;and 6 in danger positions.

.Thefield coils ofthepolarizeditrack relays at eachstation .areconnected, .:by :teed Wires-16 and .17, =with1thesecondary coil of astep-down transformer 18 energized from transmission wires. .8 and 19.The armature coilsv ofathe relays are connected with the .track coilsp12and il3, and..thus, as .thefields are constantly energized, L'theactionxofthe relaysiisrcontrolled entirely by :the currents in.tlieztraclrcoils.

The track relays control-theline circuits through their contact. fingers:19, which are normallyiheld up against contacts connected with the linewires21. WVhen-a'train enters a block, {it interrupts the current in oneof the track coils, asfabove described,:.thereby deenergizing one oi thetrack: relays, whereupon the ;contact .finger .19 :of that relay fallsand abreaksithe line circuit extending from end :torendof the block uponwhich .the;train ;is:runningand the linecircuit may also bedenergizedxand controlled, to. govern thesignals, by various conditionsother than the mere occupancy :orclear condition of. the block, iiIlfmanner well known, for instaneebythebreak inithe rail circuit orthemovement ofa sidingswitch, and .all. conditions of the blockzw'hichafi'ect the signals may beitermejd its .trafficsgoverningconditions.

The signals stand normally at danger and are set clear by electrimmotorsor. otherelectrically-controlled mechanism connected in normally, opencircuits 1 governed by. the line relays- :Uponthe entrance of a. traininto a block, both signals at *the advance end of that rblack areautomatically set clear, pro-- vided the :ineXttWo blocks in advance:are

a common return for the local circuits of both signals, which circuitsare thus normally open.

In addition to the non-polarized line relay 22, there are at eachstation two polarized relays 26 and 27. These relays are of the sametype as the track relays and their fields are connected with andconstantly energized from the feed Wires 16 and 17. The contact fingersof these relays are arranged to engage both with front contacts and withback contacts, and are moved in one direction or the other according tothe instantaneous direction of the current in their armatures relativeto the concurrent current in their fields. The armature of line relay 26is so connected as to be normally energized in a manner to cause thecontact finger to remain down against the back contact, while in linerelay 27 the contact finger is normally raised against the frontcontacts. Upon an interruption of the currents in the armatures of theserelays, the contact finger of relay 27 will fall, while that of relay 26will remain down, and upon a reversal in the phase or instantaneousdirection of the current, the contact finger of relay 27 will move orremain down while that of relay 26 will be raised to engage the frontcontacts. By means of such changes in the current in the line circuit,acting upon these line relays, the signals are selectively controlled,so that either the home signal, or both signals, or neither signal, maybe automatically set to clear upon the approach of a train.

The line circuit, in its normal condition, by which the neutral relay 22is normally energized, may now be traced. Starting at station B from theleft-hand terminal 28 of transformer 18, the current flows through wires16 and 29 to a front contact of line relay 27 and thence through thecontact finger 31 thereof, wire 32, the back contact and the contactfinger of relay 26, wire 33, coil of relay 22, wire 20, contact finger19 of track relay 14, fixed contact thereof, line wire 21, fixed contactand contact finger 19 of track relay 15", wire 34, armature coil ofrelay 27 wire 35, armature coil of relay 26 and wires 36 and 37 tocommon-return line wire'38, and thence back to B, and through wires 37and 36 to the center of the secondary winding of transformer 18 It willbe noted that the current by which the line circuit is normallyenergized is derived from the left-h and portion only of thetransformer. Suppose now that a train, moving from left to right or inan easterly direction, approaches A, and suppose that blocks AB and BCare clear. Both signals at A will now be cleared automatically to admitthe train to block A-B, in the following manner The train, upon itsentrance to the block to the left of A and so long as it remains in thatblock, acts through the the signals at the rear end of the track relaysto interrupt the line circuit through Wire 21 to the left of A. At firstthis action occurs through the track relay at the rear end of the blockto the left of A, but after the train passes the middle of the blockwhere the transformer 7 is connected to the rails, it acts byshort-circuiting the right-hand end of the block, so that coil 12 andtrack relay 14 are deenergized, and contact finger 19 of relay 1 1 fallsso as to open the line circuit at that point. The opening of the linecircuit interrupts the circuit through the coil of the non-polarizedrelay 22*, which thereupon closes the common return of the local signalcircuits through wire 25, back contact 24-, contact finger 23, and wire30. Both signals 5 and 6 are now cleared by relay 27 The signalcircuits, beginning at feed wire 16, are local and pass through wire 29to a front contact of relay 27, thence through the contact finger to theother two front contacts, thence by wires 39 and all to signals 5 and 6,respectively, and thence by the common-return wire 25, contacts of relay22, and wire 30, to feed wire 17. The signals are thereupon set clearand the train passes into block A-B. As soon as this occurs, the linecircuit of the block in rear of A is again restored by track relay 14and the non-polarized relay 22 opens the local circuits of the signalsat A, and the apparatus is restored to normal position. However themovement of the signals at A to danger does not depend on the opening ofthe contacts controlled by the line relay 22*, since the entrance of thetrain into the block AB opens the line circuit of that block (first attrack relay 15 and later at track relay 1 1 thus deenergizing both ofthe line relays 26 and 27 and positively opening the local circuits ofthe signals 5 and 6 at the contacts governed by these line relays. Theopening of the line circuit of the block.A-B de e'nergizes the linerelay 22 and thus closes its contacts to clear the signals 5 and 6 in amanner corresponding to the afore-described clearing of the signals 5and 6 Thus the signals are progressively cleared in advance of a train.

It will be noted that in the normal operation of the system in whichboth signals are cleared, the signal circuits are closed through linerelay 27. When, however, a train approaches a block which is alreadyoccupied by a train in advance, neither of block will clear; and onlythe home signal will clear at the rear end of the block in the rear ofthe occupied block. The presence of the advance train opens the linecircuit of the block occupied by that train, by de e'nergizing one orboth of the track relays l t and 15 controlled by that block. So long asthis line circuit is open, both the line relays 26 and 27 at the rearend of the block must be .denergized, as alreadypointed out, so that thelocal circuits of bojthsignals atithe rear end of Y the block are openand ;these signals areboth heldat danger. The line circuit of the blockinrear of that occupied bythe {first [train is closed at the contactsgoverned by the track-relays 1i and 15 of said rear block so that it canbe completed .by the back contacts 021 the line relays 26 .and 27,controlled by the line circuitof the block occupiedby thefirst train.This completion ofithe linecirouit ofythe block in rear vofgthe firsttrain will not effectually energize the .line relay 27 controlledbythatline circuit, but will efi'ectually energize the companion relay26, and this energization of the line relay 26 will close thenormallyopen-loca'l circuit to clear the home signal 5,.-but :will notclose the;nor mally open circuit of the companion distant signal 6. a;This actuation of line relay 26, without actuating the companion linerelay 2?, is effected :by a reversal of direction of-the current in. theline circuit. These operations will now be ,de- .scribed in-detail.Suppose the block beyond C to .the right is occupied so that the linecircuit is interrupted, either by track relay 15 or by thetrack relay atthe farther end of the block. As the current in ithe armature coilofline relay 27 is *t-hus interrupted, the relay is deenergized, and itscontact finger'fa'lls and engages itsback contact, whilethe contactfinger of line relay 26, also deenergized, remains in its normal loweredposition. By this action of relay- 27 the current normally flowing inline circuit ,,B-C, and proceeding from feed wire 16 through wire 29 isinterrupted. The line circuit BG is immediately closed again, however,.by the engagementof the contact finger of the relay 27 with its backcontact, which is connected by wire 452 with feed wire 17 This actionresults in a reversal of phase in the line circuitB-C, for the currentnow proceedsfrom'the right-hand terminal of the secondary of transformer18 through wire 43 wire 17 C and wire 4%, so that it is now theright-hand half of the transformer which energizes the line circuitl3-C. Relay 22 being non-polarized, continuesto sustain its contact.finger. At station 13 contactfinger 31 of line relay 27 falls, owing tothe reversal of phaseor instantaneous direction of current in thearmature coil ofthe relays, while the contact finger of line relay 26 israised by this reversal. The phase or direction of current in linecircuit A-B is not affected by-the operation of the line relays 26and-27 at B, for although its normal path :(f-rom feed wire ,16, throughwire 29, contactfinger 31, and wire 32, to the contact fingeroflinerelay 26 is broken by both line relays, an equivalentpath is at onceopened trom feed wire ,16 through wired? and a front con- :Etact ofrelay :26 is!) "that :the apparatus at station A remains .ininormalcondition and a train may clear both the signals at A and BIltGIEblOGkA.B. Suppose .now that the train iis in the position of arrow 45,approaching station :13 while another-train is present in the block inadvance. of the sig- .nals 0. Track relay 14 opens line circuit A -B,neutralirelay 22 is deenergized, and

:the. commonereturn of the signal. circuits is closed. Ascontactfinger.31 of line relay 27 isclown, the .signals are notlclearediin thenorrnalmanner. The home-signal 5 is cleared, however, .by a circuit completedathroughline relay 26 ,.=the contactfinger of which .has, as abovedescribed, been raised bythe reversal ,of line circuit B O. The current:fiows from deed wire 16 through wire-144E, contact'finger ofrelay 26a-second front contact and wire k6,:through wire 39 and ;home signal5,.and thenceback by common return 25 and :contactsoi' =relay22 'tosteed wire 17. The train at as thus entersblock 13 -0 :witha-cautionsignal indicated -'by theclearing of the home signal alone. The trainnew proceeds in block lB -G to :the .position of arrow 47, but neitherof thesignals atG will clear, since the contact fingers of both linerelays 26 and 27 at C are in lower position, as above described, owingto the presence of a train inthe block: beyond and-therefore'the localsignal circuits cannot be closed either through wires '39 and 41orrthrough wires 39 and 46.

It will 'be understood that although I have particularly described myinvention as applied toa system in which semaphore signals are used, theinvention is not limited toisuch application, but may be used inconnection with signals of other kinds. In

generahthe invention is not limited to the details of construction andoperation of the embodiment herein specifically described andillustrated in the drawing, but various modifications maybe made in suchembodiment withinthe nature and scope of the invention as'defined in thefollowing claims.

I claim:

1. A normal danger block signal system comprising successive signalingblocks, for each -block a line circuit and means for de- 'liveringsignal controlling current thereto,

home and distant signals for each block, means forcontrolling thecurrent in each line clrcuit by the traiiic-governing conditions df itsownblock and the block ahead that line circuit and in control of theline circuit of the block in rear, and at the rear end of each blockhome and distant signals both depending on the line circuit of thatblock for clear indications.

3. A block signal system comprising a number of successive blocks of arailway track, for each block a line circuit controllable by that block,for each line circuit one or more electro-translative devicescontrollable by that line circuit and in control of the line circuit ofthe next rear block, and at the rear end of each block home and distantsignals dependent for clear indications on said one or moreelectro-translative devices controllable by the line circuit of thatblock.

4. A railway block signaling system comprlslng successive signalingstations, at each O'opies of this patent may be obtained for five centseach, by addressing the station four relays, a circuit extending in onedirection and controlling two of said relays said two relays beingresponsive thereto in accordance with definite characters of transmittedcurrent to selectively determine the indication of the signaling meansat their respective said station, and two other circuits extending inopposite directions and arranged in control of the other two relays saidtwo remaining relays co-acting with the first two relays in the controlof said signaling means.

In testimony whereof I have afi'ixed my signature in presence of twowitnesses.

ALBERT V. 1. DAY. Witnesses:

HENRY D. WILLIAMS,

BERNARD COWEN.

Commissioner of Iatents,

Washington, D. G.

